NONLINEAR RESONANCE INTERACTION BETWEEN A FINITE-AMPLITUDE DISTURBANCE WAVE ENSEMBLE AND THE ZONAL MEAN FLOW INROTATING BAROTROPIC ATMOSPHERE

The nonlinear resonance interaction between a finite-amplitude disturbance wave ensemble and the zonal mean flow in rotating barotropic atmosphere is studied by multiple-time-scale analysis. The nonlinear triad coupling equation with dispersion and dissipation is given. The nonlinear coupling equation between wave ensembles with three modes is derived by the random phase approximation and the zero dissipation limit. The energy transfer process between finite-amplitude disturbance wave ensemble and zonal mean flow is described. The solution of coupling equation reveals that the finite-amplitude disturbancel wav心ensemble can be completely transferred into the zonal mean flow by nonlinear resonance interaction in rotating barotropic atmosphere. The energy transfer process would continue until the motion become pure zonal flow. It also reveals that the nonlinear resonance interaction is an important mechanism for the rotative adjustment.